Published on
May 10, 2017
in New York, N.Y. (USA)

U.S. Patent 8,921,332 Refers to the Use of Chimeric Endonucleases, such as Zinc Finger Nucleases, TAL-effector Nucleases, Mega-TALs and CRISPR-Cas9 to Perform Gene Insertion into Cell Genomes

May 10, 2017 – New York (N.Y.) –Cellectis (Alternext: ALCLS; Nasdaq: CLLS), a biopharmaceutical company focused on developing immunotherapies based on gene edited CAR T-cells (UCART), today announced that U.S. patent 8,921,332, which claims the use of chimeric restriction endonucleases for directing chromosomal gene editing in cells by homologous recombination (HR), initially issued on Dec. 30, 2014, has been upheld by the United States Patent and Trademark Office (USPTO) after a reexamination initiated in October 2015.

U.S. patent 8,921,332 claims a general method for modifying chromosomal DNA sequences at a genomic site of interest within a cell by using a chimeric restriction endonuclease such as zing finger nucleases, TAL-effector nucleases, Mega-TALs and CRISPR/Cas9. This technique, commonly referred to as gene targeting or targeted insertion, is now frequently used to modify the genome within plants, animals and cell lines.

The inventors of this patent are Dr. André Choulika, Cellectis’ Chairman and CEO, and Dr. Richard C. Mulligan, a Harvard Medical School Professor. Institut Pasteur and Boston Children’s Hospital, the owners of the patent, have granted exclusive rights to Cellectis under this patent. It belongs to a patent family that claims the basic uses of chimeric restriction nucleases for gene editing in cells.

Following the patent’s reexamination, the USPTO issued a Notice to Issue Reexamination Certificate in which it is stated that all 55 claims of the patent are maintained, asserting that: "The '632 patent, Smith et al., the '150 patent, Kim et al. and the '261 patent individually or in combination neither teach or suggest the method of modifying a specific sequence in a chromosomal DNA of a cell in vitro by contacting the cell with a chimeric restriction endonuclease and a targeted DNA as recited in the present claims."